Spirit mana regeneration mechanics in 2.4

Stellvia's picture

After talking with several people I realised the spirit stats isn't very well understood by people in the guild. Also seeing as it's gonna be drastically redesigned in patch 2.4 I thought it might be usefull to explain how exactly it works.

It's mostly a healer stat and more specifically a stat used by resto druids and holy priests so at some point I'll explain the mechanics for those classes. The formula are the same for all classes but i'll jsut consiuder the talents these two specs bring.

    1. the 5 second rule

In WoW there are 2 ways to regenerate mana: Spirit and items which carry the Restores X Mana Per 5 Second stat. These 2 systems work independently from one another and both restore mana in their own unique way. The primary rule to understand how spirit work is known as the 5-second rule (5SR). It goes like this:

When you complete casting a spell that requires mana, your spirit regeneration is inactive for 5 seconds.

What does this mean?
- For the first 5 seconds after finishing a spell that costs mana you are considered to be "inside the 5 second rule" or to be "in cast" or "while casting".
- The time after those 5 seconds you are "outside the 5SR" or "out of cast" or "while not casting"
- When you are outside the 5SR your spirit regeneration works at 100%
- When you are inside the 5SR your spirit regeneration works at 0%
- When you finish a spell that costs no mana (through talents, skills, items abilities or whatever) you do NOT enter the 5SR. So you can only get inside the 5SR if you spend at elast 1 mana casting a spell.
- Each time you cast a spell the 5 second timer is renewed. So if you cast a spell, you enter the 5SR and spirit regeneration drops to 0 for 5 seconds. Let's say 4 seconds after completing the first spell you complete anotehr one. The timer will then be reset and you are again inside the 5SR for 5 seconds. You stay inside the 5SR untill you manage not to finish casting a spell later than 5 seconds after the previous.

The primary rule to understand how the stat Restores X Mana Per 5 Second works is really simple:

Restores X Mana Per 5 Second will restore X mana every 5 seconds no matter what you are doing. So being inside or outside the 5SR has no importance. The 5SR ONLY applies to spirit and never to Restores X Mana Per 5 Second

If you want to regen mana through Restores X Mana Per 5 Second you don't need to do a single thing. It will be active 100% of the time. If you want to regenerate mana through Spirit you need to stop casting spells for at least 5 secodns before it becomes active. As long as you keep casting spells and stay inside the 5SR Spirit does nothing.
Your average healer will be spending about 70-80% inside the 5SR. Because Paladins and Shamans have no talent that trigger Spirit regeneration during the 5SR, spirit is essentially a useless stat for them because it is rarely active. Therefore Paladins and Shamans prefer to stack Restores X Mana Per 5 Second because this stats is active 100% of the time for them.
Priests and Druids however have a talent that allows 30% of spirit regeneration to work when they are inside the 5SR. That's why they love stacking spirit along with Restores X Mana Per 5 Second. Both of these independent mechanisms will help regenerate mana when they are inside the 5SR.

Let's look at your character sheet now: When you hover over the mana regeneration in the spell tab you'll see the two values for "while casting and "while not casting" for your character. How are these 2 values reached?

=> While not casting : it's the sum of 100% of spirit regeneration + the total amount of Restores X Mana Per 5 Second on your gear. (For shamans a small bit gets added through intellect regen talents but let's ignore that to keep it simple)
=> While casting (for druids + priests: it's the sum of 30% of spirit regeneration + the total amount of Restores X Mana Per 5 Second on your gear.

    2. the new spirit formula

The spirit regeneration formula will be changed in 2.4. It will now also depend on intellect and it is no longer different between classes (the pre 2.4 version is different for every class). It goes like this

Mana restored per 5 seconds = [Square Root (INT) / 21.5] * SPI

So what you see is that mana regeneration through the spirit mechanism will also be dependant on intellect as it depends on spirit. Essentually, intellect provides a certain coefficient by which the value of spirit is multiplied to give the mana regeneration.
Let's illustrate with an example:

Coral Band of the Revived has 27 spirit on it. Let's assume the character has 368 intellect. This means:

=> OUTSIDE the 5SR
Spirit will regenerate [Square Root (368) / 21.5] * 27 = 24.1 mana per 5 seconds outside 5SR
=> INSIDE the 5SR
Paladins and Shamans do not have a talent that makes spirit work inside the 5SR so for them the regeneration is 0 mana per 5 seconds inside 5SR
Priests and Druids have a talent that make spirit regeneration 30% active inside the 5SR so for them this becomes
Spirit will regenerate 0.30 * [Square Root (368) / 21.5] * 27 = 7.22 mana per 5 seconds inside 5SR

    3. The impact of intellect

I know many of you are by now thinking they need to start stacking intellect as well as spirit to get any spirit regeration to happen. This is not the case as the following will demonstrate.

The formula Mana restored per 5 seconds = [Square Root (INT) / 21.5] * SPI can in fact be reduced to

Mana restored per 5 seconds = C(INT) * SPI

in which C(INT) is a constant number which depends on your intellect. Let's see how big that number is for different values of intellect and what the effect is of adding 50 intellect

300 INT: C= 0.806
350 INT : C= 0.870
400 INT : C= 0.930
450 INT : C= 0.987
500 INT : C= 1.040
550 INT : C= 1.091
600 INT : C= 1.139

As you can see the effect of addign intellect lowers as you have higher intellect. At 300 intellect adding 50 intellect will increase this constant C(INT) by 0.064. At 350 adding intellect only increases it by 0.060. At 550 it allready drops to 0.048. This means:

Intellect has diminishing returns for spirit regeneration. The higher your intellect is, the less effect adding additional intellect will have. Spirit doesn't have that problem. No matter how high your spirit is, spirit will always add the same amount of regeneration. So once you have a decent mana pool it's better to stack spirit than intellect because your spirit regeneration scales faster with Spirit than with intellect.

    4. Some interesting numbers to remember

  • 1. 463 Intellect
    When you have 463 intellect the formula Mana restored per 5 seconds = [Square Root (INT) / 21.5] * SPI becomes Mana restored per 5 seconds = 1 * SPI
    This means at a value of 463 intellect adding 1 spirit to your gear will add 1 mana per 5 seconds to your "outside of the 5SR" mana regen.
  • 2. The value of 10 SPI
    Let's assume that you have 463 intellect, what is the effect of 10 spirit then on mana regen inside and outside the 5SR for priests and druids? At 463 intel 10 Spirit adds 10 mana per 5 seconds outside the 5SR and 3 mana per 5 seconds inside the 5SR. At higher values of intellect it will add even more (at 560 INT it's roughly 10% more) So an easy to remember rule to judge spirit on gear is:

    10 SPI = 10mp5 (not casting) and 10 spi = 3mp5 (when casting)

    For druids and human priests this value will be closer to 10 SPI = 11,5mp5 and 3.5 mp due to 15% spirit bonus from talents/racials

  • 2. Effective Spirit regen
    With effective spirit regeneration I mean the real amount of mana spirit will restore during a fight. During a fight you will be both inside and outside the 5SR as the battle progresses. Most healers are about 70-80% inside the 5SR during a boss fight. So what does 10 Spirit really restore? If we spend 100% outside 5SR it will be worth 10 mp5. If we spend casting 100% casting it'll be worth 3 mp5. This effective regeneration isn't a stat that appears on your character sheet. It's a stat I use to compare the real worth of an item since we usually only look at mp5 while casting. However since we do spend a large portion of time outside the 5SR as wel where the effect of spirit regen is alot bigger we need to take that into account to judge the real value. The way to calculate this is

    Mana restored per 5 seconds = (X * 0.3 * [Square Root (INT) / 21.5] * SPI) + (1-X) ( [Square Root (INT) / 21.5] * SPI)
    with X the amount of time you spend inside the 5SR. For 10 SPI this means your effective regen is

    To keep thing very simple again, we assume 463 intel (higher values of intel yield higher regen both in and out 5SR) which means [Square Root (INT) / 21.5] equals 1. We're also looking at 10 Spirit again with a 75% "in cast" fight

    Mana restored per 5 seconds = (0.75 * 0.3 * SPI) + (0.25) * SPI = 4.75

    So if you know your approximate time you spend inside the 5SR ( X ) you can use the following table to approximately judge the value of 10 SPI on an item:

    X = 60% 10SPI = 5.8 mp5 effective regen
    X = 70% 10SPI = 5.1 mp5 effective regen
    X = 75% 10SPI = 4.75 mp5 effective regen
    X = 80% 10SPI = 4.4 mp5 effective regen
    X = 90% 10SPI = 3.7 mp5 effective regen

    As you can see the longer you spend inside the 5SR the less spirit regen adds. So spammers will have less effect than slow healers. However or most our priest healers this values ranges from 70-80% depending on the fight. I find 75% a good estimate.

    5. So do i want spi or mp5 on an item then?

To end up let's compare a few items found in the T6 zones for their mana regeneration values: We're assuming at least 463 intellect to keep it simple and 75% inside the 5SR

Shroud of the Final Stand vs Shroud of Forgiveness

Instinctively most healers will say that the mp5 cloak is far better than the spirit cloak, but let's look at the mana regen these cloaks give:

1. Shroud of the Final Stand
- inside 5SR : 11mp5
- outside 5SR : 11 mp5
- effective mana regen is 11mp5

2. Shroud of Forgiveness
- inside 5SR : 20 SPI inside the 5SR is approximately (using the rule-of-thumb from above) 2 x 3mp5 = 6 mp5
- outside 5SR : 20 SPI outside the 5SR is approximately (using the rule-of-thumb from above) 2 x 10mp5 = 20 mp5
- effective regen is 9.5 mp5

As you can see these values are not so far off. In fact we didn't yet take the otehr talents priests and druids have into account. Human priests and resto druids have + 15% spirit so the spirit cloak would then yield 23 SPI. This gives the following results for regen values:
- inside 5SR : 6.9mp5
- outside 5SR : 23 mp5
- effective mana regen is 10.93mp5

So the 2 cloaks are in fact equal in regen but differ in other stats. It's up to personal preference if you prefer steady regen (mp5) over spirit regen which comes in bursts but is weaker inbetween.

Anyway if you've read so far thx for your time and i'm interested in opinions or feel free to ask questions.